August 2012
Q: Hi Steve,
I need some advice on how to preserve my airplane. I own a nice Piper Comanche 250 that I have put a lot of money into over the years. It’s just the way I want it and it’s as comfortable as an old carpet slipper.
Here’s the problem: I’ve signed a three-year contract for a good paying job overseas and I won’t be home except for very short periods. I have the Comanche in a hangar so it will be out of the weather, but I’ve heard that the Lycoming engines are very susceptible to corrosion damage if they aren’t flown regularly.
My goal is to fulfill my contract, then return home and take up flying my Comanche where I left off. Give me some tips on long-term airplane preservation.
—Going Away
A: Dear Going,
You’re wise to preserve your airplane. Too many airplanes are rotting away from lack of use and improper storage. You can see at least a half dozen sitting in misery at most small airports around the country.
There are four steps for engine preservation. First, take a short flight to get the oil up to operating temperature, drain it and refill with Phillips 66 Aviation Anti-Rust Oil 20W-50. (AeroShell 2XN is also a preservative oil.) Clean the screen or change the oil filter, then fly one short flight to distribute the clean oil throughout the engine.
The next step is to keep the engine dry. Tempest offers an engine preservation system called the AA1000 EPS in 110 and 220 Volt configurations. Tanis Aircraft sells what they call a Pickling Kit that contains everything needed to comply with the engine preservation recommendations of both Lycoming and Continental motors.
In general you will replace one spark plug in each cylinder with a dehumidifier plug; put a large bag of desiccant (the size of a large bag of M&Ms) in a heavy-duty plastic bag and tape the bag around the exhaust pipe. Repeat the desiccant/plastic bag trick on the engine crankcase breather hose.
The desiccant will absorb moisture, but you will have to recruit a helper to maintain the effectiveness of the desiccant bags. Desiccant crystals are blue when they’re dry and turn pink as they absorb moisture. (At regular intervals, remove the bags (you can remove the crystals from the dehumidifier spark plugs) and bake the crystals at no more than 300° F for three hours to remove moisture.)
Next, drain the carburetor of all fuel; drain the fuel tanks. Coat the inside of your Comanche’s bladder tanks with clean, lightweight, non-detergent engine oil to reduce drying. Remove the battery and the ELT; remove the battery from the ELT to prevent accidental alarms. Plug or cover the pitot and static tubes or ports. Plug all openings (cowling, cowl flaps, etc.) to keep out flying critters.
If you have access to an old non-serviceable set of tires, install them before cleaning and treating your good tires with a rubber preservative. None of the manufacturers recommend putting an airplane up on jacks during long-term storage, so I hesitate to recommend it—but I can’t see how it would be a problem as long as the jacks are stable and the pistons are locked in position.
If mice are a problem, I suggest that you fabricate a set of galvanized steel mouse barriers. I built a set of Mouse Attack Protectors (MAPs) by cutting three strips out of a single four-foot by eight- foot sheet of 24 gauge galvanized steel. Each strip was 16 inches wide. Two were cut 76 inches long for each main tire. The nosegear strip was 94 inches long to allow for chocks.
Each end of each strip was bent back over, so the free leg was parallel to the main sheet—toward one side at one end and toward the other side at the other end. This forms a simple nesting lock that makes MAPs easy to install and remove.
I’d also remove the avionics and take them home.
The effectiveness of these steps will be dependent on how well you do them. Performing this work under expert and/or mechanic supervision will increase your chances of success.
When you return at the end of the contract, I recommend that you hire a mechanic to do a thorough (same scope as a 100-hour) inspection and repair any discrepancies before the first flight.
Happy flying.
Q: Hi Steve;
I have a Comanche and I like the way it performs, but it’s sort of hard for me to make a good takeoff. The airplane gets light and it seems like it’s trying to fly before the book says I should rotate.
In a crosswind this causes the airplane to crow hop sideways. I don’t like it. One of the local experts told me that I need to change to the small nosewheel. He says the factory wheel is too big and it causes the airplane to go down the runway in a nose-up attitude.
Does that sound right to you? Where do I get one of these small nosewheels, and how much does it cost?
—Hopping Harvey
A: Dear Hopping,
In this case, the local expert is right. With the stock 6.00 x 6 nose tire installed (and the struts properly serviced) the wing is at a positive angle of attack. This nose-up attitude makes the airplane look unbalanced and it creates the situation you’re asking about.
It also is one of the reasons Comanches have a reputation for being hard to land; more accurately, for being prone to landing abruptly. I own a 1960 Comanche and have remedied these woes by replacing the factory nose tire with a 15 x 6.00 x 6, 6-ply rating tire. These tires are readily available. I’d recommend getting a new tube when you purchase the tire.
This modification is approved under an STC from Harlan Associates of Spruce Creek, Inc. Your Comanche will look better—and you’ll have more control during your takeoff runs and when landing.
Happy flying.
Know your FAR/AIM and check with your mechanic before starting any work
Steve Ells has been an A&P/IA for 38 years and is a commercial pilot with Instrument and Multi-Engine ratings. Ells also loves utility and bush-style airplanes and operations. He served as Associate Editor for AOPA Pilot until 2008. Ells is the owner of Ells Aviation and the proud owner of a 1960 Piper Comanche. He lives in Paso Robles, Calif. with his wife Audrey. Send questions or comments to editor@www.piperflyer.com.
RESOURCES >>>>>
Tanis Aircraft
tanisaircraft.com
Tempest Plus Marketing Group
tempestplus.com
Harlan Associates
of Spruce Creek, Inc.
Comanche Nose Tire STC
Phone (386) 405-6448
